Substituted catechol monomers, copolymers and methods for use

ABSTRACT

Disclosed are novel substituted catechol monomers, polymers made with the substituted catechol monomers, pH responsive polymers made with the substituted catechol monomers, and related methods. Also provided is a method of preparing an aqueous coating composition such as a latex paint including the above components.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/724,866 filed Aug. 30, 2018, incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to novel monomers, copolymers comprisingsuch monomers, as well as compositions and methods using such copolymersin various applications.

BACKGROUND OF THE INVENTION

Rheological additives are chemical compositions, which, added even insmall amounts, modify a liquid system's rheological properties, such asviscosity and response to shear. Such additives or thickeners may beused in a variety of liquid systems including aqueous systems such aspaints, aqueous inks, and personal care products and compositions fortreating subterranean formations. The additives improve the rheologicalproperties by also affecting the dispersion, suspension andemulsification of pigments, binders and other solids within a vehicle.

Hydrophobically modified alkali swellable emulsion (HASE, also known asHydrophobically modified alkali soluble) polymer systems and alkalisoluble emulsion (ASE) polymer systems are commonly employed to modifythe rheological properties of aqueous emulsion systems. These polymersare substantially insoluble in water at a low pH. However, at higher pHthey become swellable or soluble in water and thus exhibit thickeningbehavior. Under the influence of a base, organic or inorganic, the HASEparticles gradually swell and expand to form a three-dimensional networkby intermolecular hydrophobic aggregation between HASE copolymer chainsand/or with components of the emulsion. This network, combined with thehydrodynamic exclusion volume created by the expanded HASE chains,produces a thickening effect. This network is sensitive to appliedstress so it breaks down under shear and recovers when the stress isrelieved. Such rheological properties are particularly desirable forpaints and coatings because they make the formulation easy to apply ontoa surface while providing the thickness needed for uniform coverage andavoid spattering.

These alkali-swellable and alkali-soluble polymers are carboxylfunctional polymers synthesized by free radical polymerization.Generally, HASE copolymer systems can be prepared from the followingmonomers: (a) an ethylenically unsaturated carboxylic acid, (b) anonionic ethylenically unsaturated monomer, and (c) an ethylenicallyunsaturated hydrophobic monomer.

Latex is an example of an emulsion polymer which is a water-basedpolymer dispersion. Latex paints are used for a variety of applicationsincluding interior and exterior, and flat, semi-gloss and glossapplications. Latex is a stable dispersion (colloidal emulsion) ofrubber or plastic polymer microparticles in an aqueous medium. Latexesmay be natural or synthetic.

SUMMARY OF THE INVENTION

In one aspect, described herein are unsaturated monomers according tostructure (D.I):

whereinR₁ and R₅ are independently absent or a bivalent linking group,R₂ and R₆ are independently a bivalent polyether group,R₃ and R₇ are independently absent or a bivalent linking group, andR₄ and R₈ are independently a moiety having a site of ethylenicunsaturation;wherein R₉ and R₁₀ are independently selected from the followingstructures D.Ia, D.Ib, D.Ic, D.Id:

or a C₂-C₃₀ branched or linear alkyl group or alkenyl group.

In one embodiment, R₂ and R₆ are independently selected from—[CH(R₂₀)CH(R₂₁)O]_(x)—, wherein x is an integer of from 0 to 100, andR₂₀ and R₂₁ are independently selected from any of the following:

H; —CH₂OH; phenyl; —CH₂Cl;

a C₁-C₃₀ straight or branched alkyl or alkenyl;

—CH₂OR₂₂ wherein R₂₂ is C₁-C₃₀ straight or branched alkyl or alkenyl,phenyl, or alkyl substituted phenyl; or

R′COOCH₂— where R′ is C₁-C₃₀ straight or branched alkyl or alkenyl.

In one embodiment, R₄ and R₈ are independently according to structure(D.XV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

In another aspect, the invention is directed to pH responsive copolymerof a mixture of unsaturated copolymerizable monomers, the unsaturatedcopolymerizable monomers comprising, based on total weight of monomers:

A. about 0 to 60 weight percent, preferably 5 to 30 weight percent or 10to 45 weight percent, of at least one C₃-C₈ alpha beta-ethylenicallyunsaturated acidic monomer, preferably a C₃-C₈ alpha beta-ethylenicallyunsaturated carboxylic acid monomer;

B. about 15 to 70 weight percent, typically 20 to 50 weight percent, ofat least one non-ionic, copolymerizable C₂-C₁₂ alpha, beta-ethylenicallyunsaturated monomer; and

C. about 0.01 to 50 weight percent (wt %), or in another embodiment 0.05to 30 weight percent, or in another embodiment 0.5 to 10 weight percent,or in another embodiment 1 to 10 weight percent, or in anotherembodiment 0.5 to 9 weight percent, or in another embodiment 0.5 to 7weight percent, or in another embodiment 4 to 10 weight percent, of atleast one non-ionic ethylenically unsaturated hydrophobic monomer asdescribed herein.

The pH responsive copolymer is also known as a HASE copolymer.

The present invention also includes compositions such as aqueousdispersions comprising this pH responsive copolymer. In particular theinvention is also directed using the pH responsive copolymer as anadditive for latex binders, paints and aqueous coatings. This pHresponsive copolymer additive is used a thickener during formulation ofthe latex binders, paints and aqueous coatings, compositions fortreating subterranean formations, home care and personal care. The pHresponsive copolymer, in one embodiment, improves thickening efficiencyin aqueous coating formulations, meaning less of the pH responsivecopolymer is needed as compared with other thickeners to achieve thesame rheological profile (or thickening properties). The effect of thisthickening efficiency, in one embodiment, results in improved watersensitivity properties in the coating formulations or compositions.

The invention is also directed to a homogeneous, pourable liquid whichimproves properties in aqueous coatings, for example, improved watersensitivity. These improved properties are due to a reduction in the uselevel of the thickeners as described herein, needed to achieve a desiredrheological profile.

The aqueous coating compositions of the invention typically include atleast one latex polymer derived from at least one monomer, for exampleacrylic monomers. The at least one latex polymer in the aqueous coatingcomposition can be a pure acrylic, a styrene acrylic, a vinyl acrylic oran acrylated ethylene vinyl acetate copolymer and is more preferably apure acrylic. The at least one latex polymer is preferably derived fromat least one acrylic monomer selected from the group consisting ofacrylic acid, acrylic acid esters, methacrylic acid, and methacrylicacid esters. For example, the at least one latex polymer can be a butylacrylate/methyl methacrylate copolymer or a 2-ethylhexyl acrylate/methylmethacrylate copolymer. Typically, the at least one latex polymer isfurther derived from one or more monomers selected from the groupconsisting of styrene, alpha-methyl styrene, vinyl chloride,acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate,vinyl esters of branched tertiary monocarboxylic acids, itaconic acid,crotonic acid, maleic acid, fumaric acid, ethylene, and C₄-C₈ conjugateddienes.

Latex paint formulations typically comprise additives, e.g., at leastone pigment. In a preferred embodiment of the invention the latex paintformulation includes at least one pigment selected from the groupconsisting of TiO2, CaCO3, clay, aluminum oxide, silicon dioxide,magnesium oxide, sodium oxide, potassium oxide, talc, barytes, zincoxide, zinc sulfite and mixtures thereof. More preferably the at leastone pigment includes TiO2, calcium carbonate or clay.

In addition to the above components, the aqueous coating composition caninclude one or more additives selected from the group consisting ofdispersants, surfactants, rheology modifiers, defoamers, thickeners,biocides, mildewcides, colorants, waxes, perfumes and co-solvents.

Compositions of the present invention may have an absence of one or moreof anionic surfactant, cationic surfactant, nonionic surfactant,zwitterionic surfactant, and/or amphoteric surfactant.

These and other features and advantages of the present invention willbecome more readily apparent to those skilled in the art uponconsideration of the following detailed description, which describe boththe preferred and alternative embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to, in one embodiment, the use of aparticular family of HASE copolymers for latex dispersions, binders,paints and coatings. Described herein are aqueous compositions, forexample, aqueous coating compositions. The aqueous compositions of theinvention are aqueous polymer dispersions which include at least onelatex polymer. Paints or other aqueous coatings of the present inventiontypically further include at least one pigment. In another embodiment,the latex has a Tg of less than 30° C., more typically less than 20° C.,still more typically in the range from 10 to −10° C., e.g., 0° C. In oneembodiment, the latex has a Tg of less than 10° C., more typically lessthan 5° C., still more typically in the range from 5 to −10° C., e.g.,0° C.

As used herein, the term “alkyl” means a monovalent straight or branchedsaturated hydrocarbon radical, more typically, a monovalent straight orbranched saturated (C₁-C₄₀) hydrocarbon radical, such as, for example,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,hexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, andtetracontyl.

As used herein, the term “alkenyl” means an unsaturated straight orbranched hydrocarbon radical, more typically an unsaturated straight,branched, (C₂-C₂₂) hydrocarbon radical, that contains one or morecarbon-carbon double bonds, such as, for example, ethenyl, n-propenyl,iso-propenyl.

As used herein, the term “alkoxyl” means an oxy radical that issubstituted with an alkyl group, such as for example, methoxyl, ethoxyl,propoxyl, isopropoxyl, or butoxyl, which may optionally be furthersubstituted on one or more of the carbon atoms of the radical.

As used herein, the term “alkoxyalkyl” means an alkyl radical that issubstituted with one or more alkoxy substituents, more typically a(C₁-C₂₂)alkyloxy-(C₁-C₆)alkyl radical, such as methoxymethyl, andethoxybutyl.

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

As used herein, the term “aryl” means a monovalent unsaturatedhydrocarbon radical containing one or more six-membered carbon rings inwhich the unsaturation may be represented by three conjugated doublebonds, which may be substituted one or more of carbons of the ring withhydroxy, alkyl, alkoxyl, alkenyl, halo, haloalkyl, monocyclic aryl, oramino, such as, for example, phenyl, methylphenyl, methoxyphenyl,dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl,triisobutyl phenyl, tristyrylphenyl, and aminophenyl.

As used herein, the term “arylalkyl” means an alkyl group substitutedwith one or more aryl groups, more typically a (C₁-C₁₈)alkyl substitutedwith one or more (C₆-C₁₄)aryl substituents, such as, for example,phenylmethyl, phenylethyl, and triphenylmethyl.

As used herein, the term “aryloxy” means an oxy radical substituted withan aryl group, such as for example, phenyloxy, methylphenyl oxy,isopropylmethylphenyloxy.

As used herein, the terminology “(C_(x)-C_(y))” in reference to anorganic group, wherein x and y are each integers, indicates that thegroup may contain from x carbon atoms to y carbon atoms per group.

As used herein, the term “cycloalkenyl” means an unsaturated hydrocarbonradical, typically an unsaturated (C₅-C₂₂) hydrocarbon radical, thatcontains one or more cyclic alkenyl rings and which may optionally besubstituted on one or more carbon atoms of the ring with one or two(C₁-C₆)alkyl groups per carbon atom, such as cyclohexenyl,cycloheptenyl, and “bicycloalkenyl” means a cycloalkenyl ring systemthat comprises two condensed rings, such as bicycloheptenyl.

As used herein, the term “cycloalkyl” means a saturated hydrocarbonradical, more typically a saturated (C₅-C₂₂) hydrocarbon radical, thatincludes one or more cyclic alkyl rings, which may optionally besubstituted on one or more carbon atoms of the ring with one or two(C₁-C₆)alkyl groups per carbon atom, such as, for example, cyclopentyl,cycloheptyl, cyclooctyl, and “bicyloalkyl” means a cycloalkyl ringsystem that comprises two condensed rings, such as bicycloheptyl.

As used herein, an indication that a composition is “free” of a specificmaterial means the composition contains no measurable amount of thatmaterial.

As used herein, the term “heterocyclic” means a saturated or unsaturatedorganic radical that comprises a ring or condensed ring system,typically comprising from 4 to 16 ring atoms per ring or ring system,wherein such ring atoms comprise carbon atoms and at least oneheteroatom, such as for example, O, N, S, or P per ring or ring system,which may optionally be substituted on one or more of the ring atoms,such as, for example, thiophenyl, benzothiphenyl, thianthrenyl, pyranyl,benzofuranyl, xanthenyl, pyrolidinyl, pyrrolyl, pyradinyl, pyrazinyl,pyrimadinyl, pyridazinyl, indolyl, quinonyl, carbazolyl, phenathrolinyl,thiazolyl, oxazolyl, phenoxazinyl, or phosphabenzenyl.

As used herein, the term “hydroxyalkyl” means an alkyl radical, moretypically a (C₁-C₂₂)alkyl radical, that is substituted with one or morehydroxyl groups, such as for example, hydroxymethyl, hydroxyethyl,hydroxypropyl, and hydroxydecyl.

As used herein the term “(meth)acrylate” refers collectively andalternatively to the acrylate and methacrylate and the term“(meth)acrylamide” refers collectively and alternatively to theacrylamide and methacrylamide, so that, for example, “butyl(meth)acrylate” means butyl acrylate and/or butyl methacrylate.

As used herein, “molecular weight” in reference to a polymer or anyportion thereof, means to the weight-average molecular weight (“M_(w)”)of the polymer or portion. M_(w) of a polymer is a value measured by gelpermeation chromatography (GPC) with an aqueous eluent or an organiceluent (for example dimethylacetamide, dimethylformamide, and the like),depending on the composition of the polymer, light scattering (DLS oralternatively MALLS), viscometry, or a number of other standardtechniques. M_(w) of a portion of a polymer is a value calculatedaccording to known techniques from the amounts of monomers, polymers,initiators and/or transfer agents used to make the portion.

In one embodiment, the copolymers for use in the present inventionexhibit a weight average molecular weight, as determined by gelpermeation chromatography (GPC) and light scattering of a solution ofthe polymer in tetrahydrofuran and compared to a polystyrene standard,of greater than or equal to 30,000 grams per mole (“g/mole”). HASEthickeners may not fully dissolve in THF but after hydrolysis they candissolve in water and measurement can be run in a water gel permeationchromatography (GPC). Reference: Macromolecules 2000, 33, 2480. Forexample in a range of 30,000 to 2,000,000 g/mole.

As used herein, the indication that a radical may be “optionallysubstituted” or “optionally further substituted” means, in general,unless further limited either explicitly or by the context of suchreference, such radical may be substituted with one or more inorganic ororganic substituent groups, for example, alkyl, alkenyl, aryl,arylalkyl, alkaryl, a hetero atom, or heterocyclyl, or with one or morefunctional groups capable of coordinating to metal ions, such ashydroxyl, carbonyl, carboxyl, amino, imino, amido, phosphonic acid,sulphonic acid, or arsenate, or inorganic and organic esters thereof,such as, for example, sulphate or phosphate, or salts thereof.

As used herein, “parts by weight” or “pbw” in reference to a namedcompound refers to the amount of the named compound, exclusive, forexample, of any associated solvent. In some instances, the trade name ofthe commercial source of the compound is also given, typically inparentheses. For example, a reference to “10 pbw cocoamidopropylbetaine(“CAPB”, as MIRATAINE BET C-30)” means 10 pbw of the actual betainecompound, added in the form of a commercially available aqueous solutionof the betaine compound having the trade name “MIRATAINE BET C-30”, andexclusive of the water contained in the aqueous solution.

As used herein, an indication that a composition is “substantially free”of a specific material, means the composition contains no more than aninsubstantial amount of that material, and an “insubstantial amount”means an amount that does not measurably affect the desired propertiesof the composition.

As used herein, the term “surfactant” means a compound that reducessurface tension when dissolved in water.

“Surfactant effective amount” means the amount of the surfactant thatprovides a surfactant effect to enhance the stability of emulsions ofthe polymers.

In one embodiment, described herein are pH responsive copolymers of amixture of unsaturated copolymerizable monomers. In one embodiment,these pH responsive copolymers are substantially insoluble in water at alow pH. However, at higher pH they become swellable or soluble in waterand thus exhibit thickening behavior. Thus, the pH responsive copolymeris interchangeably termed alkali swellable copolymer or alkali solublecopolymer. Typically the pH responsive copolymer is termed analkali-soluble emulsion (ASE) copolymer and/or a hydrophobicallymodified alkali-soluble emulsion (HASE) copolymer. Although thiscopolymer is described as ASE and/or HASE copolymer it is not necessaryto make a copolymer of this structure by emulsion polymerization. Thecopolymer may also be made by solution polymerization and comes withinthe invention whether made by emulsion polymerization or solutionpolymerization.

In one embodiment, the copolymer comprises a chain of monomeric units.In a further embodiment, the copolymer is an ASE and/or HASE copolymer.The polymer is a macromolecule having a relatively high molecular massthat comprises chains of multiple repetitions of the monomeric units,which are derived, actually or conceptually, from molecules ofrelatively low molecular mass and are connected to form a linear,branched, or network structure. The copolymer typically has a linear orbranched structure, more typically single strand linear or branchedstructure. In one embodiment, a polymer having a predominantly singlestrand linear or branched structure is lightly crosslinked to form apolymer network having a low density of crosslinks. As used herein theterm “single strand” in regard to a polymer means monomeric units of thepolymer are connected such that adjacent monomeric units are joined toeach other through two atoms, one on each of the adjacent monomericunits.

The copolymer may typically be regarded as having a “backbone”, or mainpolymer chain, from which all branches and substituent groups of thepolymer may be regarded as being pendant. Where two or more chains ofthe copolymer could equally be considered to be the main chain of thepolymer, that chain is selected as the main chain which leads to thesimplest representation of the polymer molecule. The monomeric units ofthe copolymer may be arranged in random, alternating, tapered, or blocksequence along the copolymer chain.

The ASE and/or HASE copolymer typically has a weight average molecularweight of greater than or equal to about 30,000 grams per mole,typically the copolymer has a weight average molecular weight of greaterthan or equal to about 30,000 to 1,000,000 grams per mole or 30,000 to500,000 grams per mole or 50,000 to 500,000 grams per mole.

The polymer of the present invention, in one embodiment, furthercomprises one or more acidic monomeric units, each independentlycomprising at least one acid group per acidic monomeric unit.

In one embodiment, the acidic monomeric units each independentlycomprise, per monomeric unit, at least one group according to structure(B.I):—R³²—R³¹  (B.I)whereinR³¹ is a moiety that comprises at least one carboxylic acid, sulfonicacid, or phosphoric acid group, andR³² is absent or is a bivalent linking group.

In one embodiment, R³² is O, —(CH₂)_(n)—O—, or is according to structure(structure (B.II):

wherein:n is an integer of from 1 to 6,A is O or NR¹⁷, andR¹⁷ is H or (C₁-C₄)alkyl.

In one embodiment, the one or more acidic monomeric units eachindependently comprise one or two carboxy groups per monomeric unit andmay, if the acidic monomeric unit comprises a single carboxy group,further comprise an ester group according to —CH₂COOR³³, wherein R³³ isalkyl, more typically, (C₁-C₆)alkyl.

The acidic monomeric units may be made by known synthetic techniques,such as, for example, by grafting of one or more groups according tostructure (B.I) onto a polymer backbone, such as a hydrocarbon polymerbackbone, a polyester polymer backbone, or a polysaccharide polymerbackbone. In the alternative, they may be made by polymerizing a monomerthat comprises a reactive functional group and at least one groupaccording to structure (B.I) per molecule.

In one embodiment the acidic monomer comprises one or more ethylenicallyunsaturated monocarboxylic acid monomers according to structure (B.III):R³⁴—R³²—R³¹  (B.III)

wherein:

R³¹ and R³² are each as described above, and

R³⁴ is a moiety having a site of ethylenic unsaturation.

In one embodiment, R³⁴ is a α-, β-unsaturated carbonyl compound. In oneembodiment, R³⁴ is according to structure (B.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable acidic monomers include, for example, ethylenically unsaturatedcarboxylic acid monomers, such as acrylic acid and methacrylic acid,ethylenically unsaturated dicarboxylic acid monomers, such as maleicacid and fumaric acid, ethylenically unsaturated alkyl monoesters ofdicarboxylic acid monomers, such as butyl methyl maleate, ethylenicallyunsaturated sulphonic acid monomers, such as vinyl sulfonic acid2-acrylamido-2-methylpropane sulfonic acid, and styrene sulfonic acid,and ethylenically unsaturated phosphonic acid monomers, such as vinylphosphonic acid and allyl phosphonic acid, salts of any thereof, andmixtures of any thereof. Alternatively, corresponding ethylenicallyunsaturated anhydride or acid chloride monomers, such as maleicanhydride, may be used and subsequently hydrolyzed to give a pendantmoiety having two acid groups. The preferred acidic monomeric units arederived from one or more monomers selected from acrylic acid,methacrylic acid, and mixtures thereof. Methacrylic acid has thefollowing formula B. V:

In one embodiment, the polymer of the present invention furthercomprises one or more nonionic monomeric units.

In one embodiment, the nonionic monomeric units each independentlycomprise, per monomeric unit, at least one group according to structure(C.I):—R⁴²—R⁴¹  (C.I)whereinR⁴¹ is alkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, aryl, arylalkyl, oraryloxy, andR⁴² is absent or is a bivalent linking group.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, (C₁-C₂₂)hydroxyalkyl,(C₂-C₂₂)alkoxyalkyl, (C₆-C₂₄)cycloalkyl, (C₆-C₄₀)aryl, or(C₇-C₄₀)arylalkyl, more typically (C₂-C₁₂)alkyl.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, more typically, (C₁-C₁₂)alkyl.

In one embodiment, R⁴² is O, —(CH₂)_(n)—O—, wherein n is an integer offrom 1 to 6, or is according to structure (C.II):

wherein:n is an integer of from 1 to 6,A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

The nonionic monomeric units may be made by known synthetic techniques,such as, for example, by grafting of one or more groups onto a polymerbackbone, such as a hydrocarbon polymer backbone, a polyester polymerbackbone, or a polysaccharide polymer backbone, or a backbone made bypolymerization, with, for example, the above described acidic, andhydrophobic monomers and copolymerizable with the first, second, andthird monomers. Alternatively, the nonionic monomeric units may simplybe non-grafted portions of a polymer backbone.

In one embodiment, the nonionic monomeric units are derived from anonionic monomer, for example, ethyl acrylate, that comprises a reactivefunctional group, and is copolymerizable with the acidic monomers andhydrophobic monomers as described herein.

In one embodiment, the reactive functional group of the nonionic monomeris an ethylenically unsaturated group and the nonionic monomer is anethylenically unsaturated monomer comprising at least one site ofethylenic unsaturation, more typically, an α-, β-unsaturated carbonylmoiety and at least one other group.

In one embodiment, the nonionic monomer comprises one or more compoundsaccording to structure (C.III):R⁴³—R⁴²—R⁴¹  (C.III)

wherein:

R⁴¹ and R⁴² are each as described above, and

R⁴³ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (C.III) is an α-,β-unsaturated carbonyl compound. In one embodiment, R⁴³ is according tostructure (C.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable nonionic monomers include unsaturated monomers containing atleast one group according to structure C.XXIII per molecule, including(meth)acrylic esters such as: methyl (meth)acrylate, ethyl(meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate,cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl(meth)acrylate, lauryl (meth)acrylate isobornyl (meth)acrylate, benzyl(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate,phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl(meth)acrylate, tert-butylaminoethyl (meth)acrylate, and acetoxyethyl(meth)acrylate, (meth)acrylamides such as, (meth)acrylamide, N-methylol(meth)acrylamide, N-butoxyethyl (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-butyl(meth)acrylamide, N-tert-octyl (meth)acrylamide, and diacetone(meth)acrylamide, vinyl esters such as vinyl acetate, vinyl propionate,vinyl 2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, and vinylethers such as, methyl vinyl ether, ethyl vinyl ether, butyl vinylether, and hydroxybutyl vinyl ether, and ethylenically unsaturated arylcompounds, such as styrene.

In one embodiment, the HASE copolymer of the present invention iscrosslinked. A crosslinked polymer can be made by, for example, reactinga mixture of hydrophobic, first acidic, and second acidic monomers witha nonionic monomer having more than one reactive functional group, suchas for example, more than one site of ethylenic unsaturation permolecule. In one embodiment, the nonionic monomer comprises least onemonomeric compound having more than one (meth)acrylic group permolecule, such as, for example, allyl methacrylate, ethylene glycoldimethacrylate, butylene glycol dimethacrylate, diallyl pentaerythritol,methylenebisacrylamide, pentaerythritol di-, tri- and tetra-acrylates,divinyl benzene, polyethylene glycol diacrylates, bisphenol Adiacrylates, butanediol dimethacrylate, 2,2-dimethylpropanedioldimethacrylate, ethylene glycol dimethacrylate, phenylene diacrylate, ora mixture thereof.

Ethylene glycol dimethyl acrylate having the following formula

The pH responsive copolymer is made from a mixture of unsaturatedcopolymerizable monomers, wherein at least one is a novel monomercomprising, based on total weight of monomers:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent, of at least one alphabeta-ethylenically unsaturated monomer according to structure (D.I). Inone embodiment, the novel monomer according to the present inventioncomprises, based on total weight of monomers: about 0.01 to 50 weightpercent (wt %), or in another embodiment 0.05 to 30 weight percent, orin another embodiment 0.5 to 10 weight percent, or in another embodiment1 to 10 weight percent, or in another embodiment 0.5 to 9 weightpercent, or in another embodiment 0.5 to 7 weight percent, or in anotherembodiment 4 to 10 weight percent.

In one embodiment, the C₂-C₃₀ branched or linear alkyl group is a C₃-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₄-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₅-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₆-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₇-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₈-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₉-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₁₀-C₃₀branched or linear alkyl group or alkenyl group. In one embodiment, theC₂-C₃₀ branched or linear alkyl group is a C₉-C₁₄ branched or linearalkyl group or alkenyl group. In one embodiment, the C₂-C₃₀ branched orlinear alkyl group is a C₈-C₁₂ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group is aC₂₃-C₃₀ branched or linear alkyl group or alkenyl group.

In another embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₂-C₂₈ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₃-C₂₆ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₄-C₂₄ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₆-C₂₄ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₈-C₂₄ branched or linear alkyl groupor alkenyl group is a C₁₀-C₂₄ branched or linear alkyl group or alkenylgroup.

In another embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₆-C₂₀ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₂-C₃₀ branched or linear alkyl groupor alkenyl group is a C₆-C₁₈ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₂-C₃₀ branched or linear alkyl groupor alkenyl group is a C₈-C₁₆ branched or linear alkyl group or alkenylgroup.

In another embodiment, at least one of R₁, R₂ and R₃ is a branched orlinear alkyl group or alkenyl group having, as a lower limit, a C₂linear alkyl group, or in another embodiment, a C₃ branched or linearalkyl group or alkenyl group, or in another embodiment, a C₄ branched orlinear alkyl group or alkenyl group, or in a further embodiment, a C₅branched or linear alkyl group or alkenyl group, or in anotherembodiment, a C₆ branched or linear alkyl group or alkenyl group, or inyet another embodiment, a C₇ branched or linear alkyl group or alkenylgroup, or in another embodiment, a C₈ branched or linear alkyl group oralkenyl group, or in another embodiment, a C₉ branched or linear alkylgroup or alkenyl group, or in another embodiment, a C₁₀ branched orlinear alkyl group or alkenyl group, or in another embodiment, a C₁₂branched or linear alkyl group or alkenyl group, or in anotherembodiment, a C₁₄ branched or linear alkyl group or alkenyl group, or inyet a further embodiment, a C₁₆ branched or linear alkyl group oralkenyl group.

In one embodiment, R₄ and R₈ are independently each according tostructure (D.XV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

The C₂-C₃₀ branched or linear alkyl group or alkenyl group can be aC₃-C₁₄ branched or linear alkyl group or alkenyl group, or a C₆-C₁₄branched or linear alkyl group or alkenyl group, or a C₈-C₁₂ branched orlinear alkyl group or alkenyl group, or a C₄-C₁₂ branched or linearalkyl group or alkenyl group. Preferably, The C₂-C₃₀ branched or linearalkyl group or alkenyl group can be a C₈-C₁₂ branched or linear alkylgroup or alkenyl group, or a C₄-C₁₂ branched or linear alkyl group oralkenyl group.

In one embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₃-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₄-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₅-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₆-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₇-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₈-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₉-C₃₀ branched or linear alkyl group or alkenyl group. Inone embodiment, the C₂-C₃₀ branched or linear alkyl group or alkenylgroup is a C₁₀-C₃₀ branched or linear alkyl group or alkenyl group.

In another embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₂-C₂₈ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₃-C₂₆ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₄-C₂₄ branched or linear alkyl group or alkenylgroup. In one embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₆-C₂₄ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₈-C₂₄ branched or linear alkyl groupor alkenyl group is a C₁₀-C₂₄ branched or linear alkyl group or alkenylgroup.

In another embodiment, the C₂-C₃₀ branched or linear alkyl group oralkenyl group is a C₆-C₂₀ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₂-C₃₀ branched or linear alkyl groupor alkenyl group is a C₆-C₁₈ branched or linear alkyl group or alkenylgroup. In another embodiment, the C₂-C₃₀ branched or linear alkyl groupor alkenyl group is a C₈-C₁₆ branched or linear alkyl group or alkenylgroup.

In one embodiment, R₁, R₃, R₅, R₇ are each independently O, a bivalenthydrocarbon group, even more typically a methylene group or chain offrom 2 to 6 methylene units, or a bivalent alkyleneoxyl group, such asethyleneoxy. In one embodiment, R₁, R₃, R₅, R₇ are independentlyaccording to structure (D.VIII):—(CH₂)_(b)-A-  (D.IX)wherein A is O or absent, and b is an integer of from 1 to 6.

In some embodiments, R₂ and R₆ are independently a bivalent polyethergroup comprising a linear chain of from 2 to 100 units, each of whichmay independently be (C₂-C₄)oxyalkylene, more typically,(C₂-C₃)oxyalkylene. In one embodiment, R₂ and R₆ are independently abivalent polyether group comprising a chain of from 2 to 100 polymerizedoxyethylene units and oxypropylene units, which may be arrangedalternately, randomly, or in blocks. In one embodiment, R₂ and R₆ areindependently a bivalent polyether group comprising a block ofpolyoxyethylene units and a block of oxypropylene units, more typically,a block of polyoxyethylene units and a block of oxypropylene units,wherein the block of oxypropylene units is disposed between and linksthe block of oxyethylene units and the R¹² substituent, if present, orthe R¹¹ substituent, if R¹² is not present.

In one embodiment, R₁, R₃, R₅, R₇ are each independently —(CH₂)_(x)O—,wherein x is an integer from 1 to 20 (e.g., use of styrenated benzylalcohols)

In another embodiment, R₁, R₃, R₅, R₇ are each independently—CH₂CH(OH)CH₂O— or —CH₂CH(CH₂OH)O— (e.g., use of epichlorohydrin ascoupling agent)

In one embodiment, R₂ and R₆ are independently:

—[CH(R₂₀)CH(R₂₁)O]_(x)— wherein x is an integer of from 0 to 100, andR₂₀ and R₂₁ are independently selected from any of the following:

H; —CH₂OH; phenyl; —CH₂Cl;

a C₁-C₃₀ straight or branched alkyl or alkenyl;

—CH₂OR₂₂ wherein R₂₂ is C₁-C₃₀ straight or branched alkyl or alkenyl,phenyl, or alkyl substituted phenyl; or

R′COOCH₂— where R′ is C₁-C₃₀ straight or branched alkyl or alkenyl.

The hydrophobic monomeric units may be made by known synthetictechniques, such as, for example, by grafting of one or more groupsaccording to structure (D.I) onto a polymer backbone, such as ahydrocarbon polymer backbone, a polyester polymer backbone, or apolysaccharide polymer backbone, or by copolymerization, with, forexample, the acidic monomer and nonionic monomer described above, of atleast one other monomer selected from monomers that comprise a reactivefunctional group and at least one group according to structure (D.I) permolecule.

In one embodiment, the hydrophobic monomeric units are derived from atleast one hydrophobic monomer selected from monomers that comprise areactive functional group and at least one group according to structure(D.I) per molecule.

In one embodiment, the reactive functional group of the first monomer isan ethylenically unsaturated group. Thus, the hydrophobic monomer isselected from ethylenically unsaturated monomers that comprise at leastone site of ethylenic unsaturation, more typically, an α-, β-unsaturatedcarbonyl moiety, and least one group according to structure (I) permolecule.

Making the ASE and/or HASE Copolymer

The pH responsive copolymer is the product of copolymerization of amixture of monomers, comprising:

A. about 0-60 weight percent, preferably 5 to 30 weight percent, of atleast one C3-C8 alpha beta-ethylenically unsaturated acidic monomer,preferably a C3-C8 alpha beta-ethylenically unsaturated carboxylic acidmonomer;

B. about 15-70 weight percent, typically 20 to 50 weight percent, of atleast one non-ionic, copolymerizable C2-C12 alpha, beta-ethylenicallyunsaturated monomer.

C. about 0.01 to 30 weight percent, preferably 0.05 to 30 weight percentor typically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomer.

The pH responsive copolymer of the present invention can be convenientlyprepared from the above-described monomers by known aqueous emulsionpolymerization techniques using free-radical producing initiators,typically in an amount from 0.01 percent to 3 percent, based on theweight of the monomers.

In one embodiment, the polymerization is conducted at a pH of about 5.0or less. Polymerization at an acid pH of about 5.0 or less permitsdirect preparation of an aqueous colloidal dispersion having relativelyhigh solids content without the problem of excessive viscosity.

In one embodiment, the polymerization is conducted in the presence ofone or more free-radical producing initiators selected from peroxygencompounds. Useful peroxygen compounds include inorganic persulfatecompounds such as ammonium persulfate, potassium persulfate, sodiumpersulfate, peroxides such as hydrogen peroxide, organic hydroperoxides,for example, cumene hydroperoxide, and t-butyl hydroperoxide, organicperoxides, for example, benzoyl peroxide, acetyl peroxide, lauroylperoxide, peracetic acid, and perbenzoic acid (sometimes activated by awater-soluble reducing agent such as ferrous compound or sodiumbisulfite), and other free-radical producing materials or techniquessuch as 2,2′-azobisisobutyronitrile and high energy radiation sources.

In one embodiment, the polymerization is conducted in the presence ofone or more emulsifiers. Useful emulsifiers include anionic surfactants,nonionic surfactants, amphoteric surfactants, and zwitterionicsurfactants. In one embodiment, the emulsion polymerization is conductedin the presence of one or more anionic surfactants. Examples of anionicemulsifiers are the alkali metal alkyl aryl sulfonates, the alkali metalalkyl sulfates and the sulfonated alkyl esters. Specific examples ofthese well-known emulsifiers are sodium dodecyl benzene sulfonate,sodium dodecyl butylnaphthalene sulfonate, sodium lauryl sulfate,disodium dodecyl diphenyl ether disulfonate, disodium n-octadecylsulfosuccinamate and sodium dioctyl sulfosuccinate. Known nonionicemulsifiers include, for example, fatty alcohols, alkoxylated fattyalcohols, and alkylpolyglucosides.

The emulsion polymerization may, optionally, be conducted in thepresence, in an amount up to about 10 parts per 100 parts ofpolymerizable monomers, of one or more chain transfer agents.Representative chain transfer agents are carbon tetrachloride,bromoform, bromotrichloromethane, and long-chain alkyl mercaptans andthioesters, such as n-dodecyl mercaptan, t-dodecyl mercaptan, octylmercaptan, tetradecyl mercaptan, hexadecyl mercaptan, butylthioglycolate, isooctyl thioglycolate, and dodecyl thioglycolate.

Optionally, other ingredients well known in the emulsion polymerizationart may be included, such as chelating agents, buffering agents,inorganic salts and pH adjusting agents.

In one embodiment, the polymerization is carried out at a temperaturebetween about 60° C. and 90° C., but higher or lower temperatures may beused. The polymerization can be conducted batchwise, stepwise, orcontinuously with batch and/or continuous addition of the monomers, in aconventional manner.

The monomers can be copolymerized in such proportions, and the resultingemulsion polymers can be physically blended, to give products with thedesired balance of properties for specific applications. For example,for analogous polymers of a given molecular weight, increasing theamount of first monomer tends to increase the yield strength exhibitedby the polymer, increasing the relative amount of second monomer tendsto increase the viscosity of the polymer. One or more fourth monomersmay be added to adjust the properties of the polymer.

These polymeric products prepared by emulsion polymerization at an acidpH are in the form of stable aqueous colloidal dispersions containingthe polymer dispersed as discrete particles having average particlediameters of about 400 to about 3000 Å (40 to 300 nanometers) andpreferably about 600 to about 1750 Å (60 to 175 nanometers), as measuredby light scattering. Dispersions containing polymer particles smallerthan about 400 Å (40 nanometers) are difficult to stabilize, whileparticles larger than about 3000 Å (300 nanometers) reduce the ease ofdispersion in the aqueous products to be thickened.

In one embodiment, the polymer composition is in the form of an aqueouspolymer dispersion, typically having a solids content including thepolymer and any surfactants that may be present and based on the totalweight of the polymer dispersion, of up to about 60 wt % and, moretypically about 20 to about 50 wt %.

Alternatively this (co)polymerization may also be conducted by differentmethods or in different solvents. The scope of methods and solvents iswell known to those skilled in the art.

Thus, these polymers for use in the present invention can be made usingknown solution polymerization techniques, wherein the reactant monomersand initiator are dissolved in an appropriate solvent such as toluene,xylene, tetrahydrofuran, or mixtures thereof. Polymerization can beaccomplished in the time and at the temperature necessary, e.g., 60° C.to 80° C. and about 2 to 24 hours. The polymer product can be isolatedthrough normal separation techniques, including solvent stripping.

In one embodiment, these polymers for use in the present inventionexhibit a weight average molecular weight, as determined by gelpermeation chromatography and light scattering of a solution of thepolymer in tetrahydrofuran and compared to a polystyrene standard, ofgreater than or equal to 30,000 grams per mole (“g/mole”). HASEthickeners may not fully dissolve in THF but after hydrolysis they candissolve in water and measurement can be run in a water gel permeationchromatography (GPC). Reference: Macromolecules 2000, 33, 2480. Forexample in a range of 30,000 to 5,000,000 g/mole. More typically thepolymer of the present invention exhibits a weight average molecularweight of from about 100,000 g/mole, and even more typically from about150,000 g/mole, to about 1,500,000 g/mole, more typically to about1,000,000 g/mole, and even more typically to about 800,000 g/mole.

In one embodiment, these pH responsive copolymers for use in the presentinvention are in the form of an aqueous colloidal polymer dispersion.When the polymer composition is in the form of an aqueous colloidalpolymer dispersion, the composition is maintained at a pH of about 5 orless to maintain stability. More typically, the aqueous colloidalpolymer dispersion composition has a pH of about 1.5 to about 3. Whenthickening of the composition is desired, the pH of the composition canbe increased to a value above about 5 by addition of a base tosolubilize the polymer.

These ASE and HASE copolymers and compositions for use as thickeners inthe present invention are pH-responsive. At the lower pH levels at whichthe emulsion polymerization takes place, i.e., pH levels of 5 or less,the composition is relatively thin or non-viscous. When the pH of thecopolymer dispersion is neutralized or adjusted by addition of a base toa pH of about 5.5 or more, preferably about 6 to about 11, thecomposition thickens substantially. The composition turns fromsemi-opaque or opaque to translucent or transparent as viscosityincreases. Viscosity increases as copolymer dissolves partially orcompletely in the aqueous phase of the composition. Neutralization canoccur in situ when the emulsion copolymer is blended with the base andadded to the aqueous phase. Or, if desired for a given application,neutralization can be carried out when blending with an aqueous product.Useful bases include, but are not limited to, ammonium hydroxide, anamine, sodium hydroxide, potassium carbonate or the like.

For example, the HASE copolymer having a polymer backbone including MAAand EA is a pH-sensitive thickener. Typically the copolymer is a latexat pH=2.3. When neutralized with a suitable base to a pH above about5.5, the carboxyl groups on the methacrylic acid ionize to carboxylateions. The charge on the polymer induces a conformational change, and thewhite latex becomes water-soluble, thus increasing the hydrodynamicvolume of the polymer. When the HASE copolymers swell, the pendanthydrophobic groups are free to build associations with one another andwith other hydrophobes available in the formulation, such assurfactants, particulates, emulsion droplets and dyes. This phenomenoncreates a network structure that results in a significant viscositybuild.

IV. Uses of the pH Responsive Polymer

The polymers and polymer compositions according to the present inventionare useful as water-soluble thickeners for a wide variety ofapplications ranging from home care, personal care and oilfield drillingfluids. They are particularly useful for aqueous paints and coatings.Solution-polymerized polymers can be used in solvent systems oremulsified by known techniques for use in aqueous systems. Other usesinclude latexes and detergents. Useful cosmetic compositions willtypically have an aqueous carrier, a pigment and/or cosmetic active, aHASE emulsion polymer, and optional adjuvants. Useful detergents andcleansers will typically have aqueous carrier, a HASE emulsion polymer,and optional adjuvants. Oilfield drilling fluids will typically have anaqueous carrier, HASE emulsion polymer as a thickener/viscositymodifier, and optional adjuvants. The oilfield drilling fluids areinjected into the oilfield formation. Useful latex coatings willtypically have an aqueous carrier, a HASE emulsion polymer, and optionaladjuvants.

The HASE emulsion polymers according to the present invention asdescribed herein are particularly useful as thickeners for a widevariety of water-based compositions. Such compositions include brine,slurries, and colloidal dispersions of water-insoluble inorganic andorganic materials, such as natural rubber, synthetic or artificiallatexes. The emulsion polymers of the invention are especially useful inareas requiring thickening at neutral pHs, such as in cosmetics.

In one embodiment, the aqueous composition comprising the pH responsivepolymer of the present invention exhibits viscoelastic properties atneutral to alkaline pH values, typically at pH values greater than orequal to about 5, more typically greater than or equal to about 5.5,even more typically from about 6 to about 9.

IV. Use of the pH Responsive Polymer with Binders which are LatexPolymers

Embodiments of the invention, such as latex paint, may contain more thanone category of latex. There can be a first latex namely, the HASEcopolymer, as a thickener. There can also be a second latex, for exampleRHOPLEX SG30 or REVACRYL synthetic latex emulsion resins, as a binderfor latex paint.

Synthetic latexes take the form of aqueous dispersions/suspensions ofparticles of latex polymers. Synthetic latexes include aqueous colloidaldispersions of water-insoluble polymers prepared by emulsionpolymerization of one or more ethylenically unsaturated monomers.Typical of such synthetic latexes are emulsion copolymers ofmonoethylenically unsaturated compounds, such as styrene, methylmethacrylate, acrylonitrile with a conjugated diolefin, such asbutadiene or isoprene; copolymers of styrene, acrylic and methacrylicesters, copolymers of vinyl halide, vinylidene halide, vinyl acetate andthe like. Many other ethylenically unsaturated monomers or combinationsthereof can be emulsion polymerized to form synthetic latexes. Suchlatexes are commonly employed in paints (latex paints) and coatings. Thecomposition of the present invention may be added to latexes tomodify/increase viscosity.

The polymeric thickeners of this invention are advantageous for use withthe water-based compositions according to the foregoing description andwith compositions containing those materials, especially coatingcompositions of various types. Mixtures or combinations of two or morethickeners may be used, if desired. Of course the latex polymers used incoating compositions are preferably film-forming at temperatures about25 degrees C. or less, either inherently or through the use ofplasticizers. Such coating compositions include water-based consumer andindustrial paints; sizing, adhesives and other coatings for paper,paperboard, textiles; and the like.

Latex paints and coatings may contain various adjuvants, such aspigments, fillers and extenders. Useful pigments include, but are notlimited to, titanium dioxide, mica, and iron oxides. Useful fillers andextenders include, but are not limited to, barium sulfate, calciumcarbonate, clays, talc, and silica. The compositions of the presentinvention described herein are compatible with most latex paint systemsand provide highly effective and efficient thickening.

The polymer compositions of the present invention may be added toaqueous product systems at a wide range of amounts depending on thedesired system properties and end use applications. In latex paints, thecomposition is added such that the emulsion (HASE) polymer according tothe present invention is present at about 0.05 to about 5.0 weightpercent and preferably about 0.1 to about 3.0 weight percent based ontotal weight of the latex paint, including all of its components, suchas water, HASE polymer, latex polymer, pigment, and any adjuvants.

The present invention also includes a method of preparing an aqueouscoating composition by mixing together at least one latex polymerderived from at least one monomer and blended with at least one pHresponsive copolymer as described above, and at least one pigment.Preferably, the latex polymer is in the form of latex polymerdispersion. The additives discussed above can be added in any suitableorder to the latex polymer, the pigment, or combinations thereof, toprovide these additives in the aqueous coating composition. In the caseof paint formulations, the aqueous coating composition preferably has apH of from 7 to 10.

In formulating latexes and latex paints/coatings, physical propertiesthat may be considered include, but are not limited to, viscosity versusshear rate, ease of application to surface, spreadability, and shearthinning.

V. Emulsion Polymerization to Make Latex Binder for Latex Paint

Emulsion polymerization is discussed in G. Pohlein, “EmulsionPolymerization”, Encyclopedia of Polymer Science and Engineering, vol.6, pp. 1-51 (John Wiley & Sons, Inc., NY, NY, 1986), the disclosure ofwhich is incorporated herein by reference. Emulsion polymerization is aheterogeneous reaction process in which unsaturated monomers or monomersolutions are dispersed in a continuous phase with the aid of anemulsifier system and polymerized with free-radical or redox initiators.The product, a colloidal dispersion of the polymer or polymer solution,is called a latex.

The monomers typically employed in emulsion polymerization to make latexfor latex paint include such monomers as methyl acrylate, ethylacrylate, methyl methacrylate, butyl acrylate, 2-ethyl hexyl acrylate,other acrylates, methacrylates and their blends, acrylic acid,methacrylic acid, styrene, vinyl toluene, vinyl acetate, vinyl esters ofhigher carboxylic acids than acetic acid, e.g. vinyl versatate,acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride and thelike, and mixtures thereof. This is further discussed below in thesection entitled “Latex Monomers”.

In the above process, suitable initiators, reducing agents, catalystsand surfactants are well known in the art of emulsion polymerization.Typical initiators include ammonium persulfate (APS), hydrogen peroxide,sodium, potassium or ammonium peroxydisulfate, dibenzoyl peroxide,lauryl peroxide, ditertiary butyl peroxide, 2,2′-azobisisobutyronitrile,t-butyl hydroperoxide, benzoyl peroxide, and the like. Commonly usedredox initiation systems are described e.g., by A. S. Sarac in Progressin Polymer Science 24(1999), 1149-1204.

Suitable reducing agents are those which increase the rate ofpolymerization and include for example, sodium bisulfite, sodiumhydrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid,isoascorbic acid, and mixtures thereof.

Suitable catalysts are those compounds which increase the rate ofpolymerization and which, in combination with the above-describedreducing agents, promote decomposition of the polymerization initiatorunder the reaction conditions. Suitable catalysts include transitionmetal compounds such as, for example, ferrous sulfate heptahydrate,ferrous chloride, cupric sulfate, cupric chloride, cobalt acetate,cobaltous sulfate, and mixtures thereof.

Emulsion polymerization occurs in the presence of an emulsifier.Typically the mixture contains 0.5 to 6 wt % emulsifier based on weightof latex monomers

Typical emulsifiers are ionic or non-ionic surfactants polymerizable ornon-polymerizable in the aqueous coating composition including latexpolymer. Suitable ionic and nonionic surfactants are alkyl polyglycolethers such as ethoxylation products of lauryl, tridecyl, oleyl, andstearyl alcohols; alkyl phenol polyglycol ethers such as ethoxylationproducts of octyl- or nonylphenol, diisopropyl phenol, triisopropylphenol; alkali metal or ammonium salts of alkyl, aryl or alkylarylsulfonates, sulfates, phosphates, and the like, including sodium laurylsulfate, sodium octylphenol glycolether sulfate, sodium dodecylbenzenesulfonate, sodium lauryldiglycol sulfate, and ammonium tritertiarybutylphenol and penta- and octa-glycol sulfonates, sulfosuccinate salts suchas disodium ethoxylated nonylphenol half ester of sulfosuccinic acid,disodium n-octyldecyl sulfosuccinate, sodium dioctyl sulfosuccinate, andthe like.

The polymer latex binder can be produced by first preparing an initiatorsolution comprising the initiator and water. A monomer pre-emulsion isalso prepared comprising one or more surfactants (emulsifiers), andother latex monomers to be used to form the latex polymer, water, andadditional additives such as NaOH.

Thus, a typical process of emulsion polymerization preferably involvescharging water to a reactor and feeding as separate streams apre-emulsion of the monomer and a solution of the initiator. Inparticular, the polymer latex binder can be prepared using emulsionpolymerization by feeding the monomers used to form the latex binder toa reactor in the presence of at least one initiator and at least onesurfactant and polymerizing the monomers to produce the latex binder.Typically the initiator solution and monomer pre-emulsion arecontinuously added to the reactor over a predetermined period of time(e.g. 1.5-5 hours) to cause polymerization of latex monomers to producethe latex polymer.

Prior to the addition of the initiator solution and the monomerpre-emulsion, a seed latex such as a polystyrene seed latex can be addedto the reactor. For example, a small amount of the pre-emulsion and aportion of the initiator may be charged initially at the reactiontemperature to produce “seed” latex. The “seed” latex procedure resultsin better particle-size reproducibility.

Under “normal” initiation conditions, that is initiation conditionsunder which the initiator is activated by heat, the polymerization isnormally carried out at about 60-90° C. A typical “normal” initiatedprocess, for example, could employ ammonium persulfate as initiator at areaction temperature of 80+/−2° C. Under “redox” initiation conditions,namely initiation conditions under which the initiator is activated by areducing agent, the polymerization is normally carried out at 60-70° C.Normally, the reducing agent is added as a separate solution. A typical“redox” initiated process, for example, could employ potassiumpersulfate as the initiator and sodium metabisulfite as the reducingagent at a reaction temperature of 65+/−2° C.

The reactor is operated at desired reaction temperature at least untilall the monomers are fed to produce the polymer latex binder. Once thepolymer latex binder is prepared, it is preferably chemically strippedthereby decreasing its residual monomer content. Preferably, it ischemically stripped by continuously adding an oxidant such as a peroxide(e.g. t-butylhydroperoxide) and a reducing agent (e.g. sodium acetonebisulfite), or another redox pair such as those described by A. S. Saracin Progress in Polymer Science 24(1999), 1149-1204, to the latex binderat an elevated temperature and for a predetermined period of time (e.g.0.5 hours). The pH of the latex binder can then be adjusted and otheradditives added after the chemical stripping step.

In the above emulsions, the polymer preferably exists as a generallyspherical particle, dispersed in water, with a diameter of about 50nanometers to about 500 nanometers.

For purposes of this description, monomers from which latex polymers maybe derived are termed “latex monomers”.

The latex monomers fed to a reactor to prepare the polymer latex binderpreferably include at least one acrylic monomer selected from the groupconsisting of acrylic acid, acrylic acid esters, methacrylic acid, andmethacrylic acid esters. In addition, the monomers can include styrene,vinyl acetate, or ethylene. The monomers can also include one or moremonomers selected from the group consisting of styrene, (alpha)-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureidomethacrylate, vinyl acetate, vinyl esters of branched tertiarymonocarboxylic acids (e.g. vinyl esters commercially available under themark VEOVA from Shell Chemical Company or sold as EXXAR neo vinyl estersby ExxonMobil Chemical Company), itaconic acid, crotonic acid, maleicacid, fumaric acid, and ethylene. It is also possible to include C4-C8conjugated dienes such as 1,3-butadiene, isoprene or chloroprene.Commonly used monomers in making acrylic paints are butyl acrylate,methyl methacrylate, ethyl acrylate and the like. Preferably, themonomers include one or more monomers selected from the group consistingof n-butyl acrylate, methyl methacrylate, styrene and 2-ethylhexylacrylate.

The latex polymer is typically selected from the group consisting ofpure acrylics (comprising acrylic acid, methacrylic acid, an acrylateester, and/or a methacrylate ester as the main monomers); styreneacrylics (comprising styrene and acrylic acid, methacrylic acid, anacrylate ester, and/or a methacrylate ester as the main monomers); vinylacrylics (comprising vinyl acetate and acrylic acid, methacrylic acid,an acrylate ester, and/or a methacrylate ester as the main monomers);and acrylated ethylene vinyl acetate copolymers (comprising ethylene,vinyl acetate and acrylic acid, methacrylic acid, an acrylate ester,and/or a methacrylate ester as the main monomers). The monomers can alsoinclude other main monomers such as acrylamide and acrylonitrile, andone or more functional monomers such as itaconic acid and ureidomethacrylate, as would be readily understood by those skilled in theart. In a particularly preferred embodiment, the latex polymer is a pureacrylic such as a butyl acrylate/methyl methacrylate copolymer derivedfrom monomers including butyl acrylate and methyl methacrylate.

In typical acrylic paint compositions the polymer is comprised of one ormore esters of acrylic or methacrylic acid, typically a mixture, e.g.about 50/50 by weight, of a high T_(g) monomer (e.g. methylmethacrylate) and a low T_(g) monomer (e.g. butyl acrylate), with smallproportions, e.g. about 0.5% to about 2% by weight, of acrylic ormethacrylic acid. The vinyl-acrylic paints usually include vinyl acetateand butyl acrylate and/or 2-ethyl hexyl acrylate and/or vinyl versatate.In vinyl-acrylic paint compositions, at least 50% of the polymer formedis comprised of vinyl acetate, with the remainder being selected fromthe esters of acrylic or methacrylic acid. The styrene/acrylic polymersare typically similar to the acrylic polymers, with styrene substitutedfor all or a portion of the methacrylate monomer thereof.

The latex polymer dispersion preferably includes from about 30 to about75% solids and a mean latex particle size of from about 70 to about 650nm. The latex polymer is preferably present in the aqueous coatingcomposition in an amount from about 5 to about 60 percent by weight, andmore preferably from about 8 to about 40 percent by weight (i.e. theweight percentage of the dry latex polymer based on the total weight ofthe coating composition).

The aqueous coating composition is a stable fluid that can be applied toa wide variety of materials such as, for example, paper, wood, concrete,metal, glass, ceramics, plastics, plaster, and roofing substrates suchas asphaltic coatings, roofing felts, foamed polyurethane insulation; orto previously painted, primed, undercoated, worn, or weatheredsubstrates. The aqueous coating composition of the invention can beapplied to the materials by a variety of techniques well known in theart such as, for example, brush, rollers, mops, air-assisted or airlessspray, electrostatic spray, and the like.

V. Liquid Carrier

In one embodiment, the composition of the present invention comprisesthe selected polymer and a liquid carrier.

In one embodiment, the liquid carrier is an aqueous carrier comprisingwater and the treatment solution is in the form of a solution, emulsion,or dispersion of the material and additives. In one embodiment, theliquid carrier comprises water and a water miscible organic liquid.Suitable water miscible organic liquids include saturated or unsaturatedmonohydric alcohols and polyhydric alcohols, such as, for example,methanol, ethanol, isopropanol, cetyl alcohol, benzyl alcohol, oleylalcohol, 2-butoxyethanol, and ethylene glycol, as well as alkyletherdiols, such as, for example, ethylene glycol monoethyl ether, propyleneglycol monoethyl ether and diethylene glycol monomethyl ether.

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

VI. Other Additives

As described above, latex paints and coatings may contain variousadjuvants.

The aqueous coating compositions of the invention include less than 2%by weight and preferably less than 1.0% by weight of anti-freeze agentsbased on the total weight of the aqueous coating composition. Forexample, the aqueous coating compositions may be substantially free ofanti-freeze agents.

The aqueous coating composition typically includes at least one pigment.The term “pigment” as used herein includes non-film-forming solids suchas pigments, extenders, and fillers. The at least one pigment ispreferably selected from the group consisting of TiO2 (in both anastaseand rutile forms), clay (aluminum silicate), CaCO3 (in both ground andprecipitated forms), aluminum oxide, silicon dioxide, magnesium oxide,talc (magnesium silicate), barytes (barium sulfate), zinc oxide, zincsulfite, sodium oxide, potassium oxide and mixtures thereof. Suitablemixtures include blends of metal oxides such as those sold under themarks MINEX (oxides of silicon, aluminum, sodium and potassiumcommercially available from Unimin Specialty Minerals), CELITES(aluminum oxide and silicon dioxide commercially available from CeliteCompany), ATOMITES (commercially available from English China ClayInternational), and ATTAGELS (commercially available from Engelhard).More preferably, the at least one pigment includes TiO2, CaCO3 or clay.Generally, the mean particle sizes of the pigments range from about 0.01to about 50 microns. For example, the TiO2 particles used in the aqueouscoating composition typically have a mean particle size of from about0.15 to about 0.40 microns. The pigment can be added to the aqueouscoating composition as a powder or in slurry form. The pigment ispreferably present in the aqueous coating composition in an amount fromabout 5 to about 50 percent by weight, more preferably from about 10 toabout 40 percent by weight.

The coating composition can optionally contain additives such as one ormore film-forming aids or coalescing agents. Suitable firm-forming aidsor coalescing agents include plasticizers and drying retarders such ashigh boiling point polar solvents. Other conventional coating additivessuch as, for example, dispersants, additional surfactants (i.e. wettingagents), rheology modifiers, defoamers, thickeners, additional biocides,additional mildewcides, colorants such as colored pigments and dyes,waxes, perfumes, co-solvents, and the like, can also be used inaccordance with the invention. For example, non-ionic and/or ionic (e.g.anionic or cationic) surfactants can be used to produce the polymerlatex. These additives are typically present in the aqueous coatingcomposition in an amount from 0 to about 15% by weight, more preferablyfrom about 1 to about 10% by weight based on the total weight of thecoating composition.

The aqueous coating composition typically includes less than 10.0% ofanti-freeze agents based on the total weight of the aqueous coatingcomposition. Exemplary anti-freeze agents include ethylene glycol,diethylene glycol, propylene glycol, glycerol (1,2,3-trihydroxypropane),ethanol, methanol, 1-methoxy-2-propanol, 2-amino-2-methyl-1-propanol,and FTS-365 (a freeze-thaw stabilizer from Inovachem SpecialtyChemicals). More preferably, the aqueous coating composition includesless than 5.0% or is substantially free (e.g. includes less than 0.1%)of anti-freeze agents. Accordingly, the aqueous coating composition ofthe invention preferably has a VOC level of less than about 100 g/L andmore preferably less than or equal to about 50 g/L.

The balance of the aqueous coating composition of the invention iswater. Although much of the water is present in the polymer latexdispersion and in other components of the aqueous coating composition,water is generally also added separately to the aqueous coatingcomposition. Typically, the aqueous coating composition includes fromabout 10% to about 85% by weight and more preferably from about 35% toabout 80% by weight water. Stated differently, the total solids contentof the aqueous coating composition is typically from about 15% to about90%, more preferably, from about 20% to about 65%.

The coating compositions are typically formulated such that the driedcoatings comprise at least 10% by volume of dry polymer solids, andadditionally 5 to 90% by volume of non-polymeric solids in the form ofpigments. The dried coatings can also include additives such asplasticizers, dispersants, surfactants, rheology modifiers, defoamers,thickeners, additional biocides, additional mildewcides, colorants,waxes, and the like, that do not evaporate upon drying of the coatingcomposition.

In one embodiment, the present invention is directed to a home care orindustrial cleaning composition, such as a liquid detergent, a laundrydetergent, a hard surface cleanser, a dish wash liquid, or a toilet bowlcleaner, comprising water, one or more surfactants, and a polymer of thepresent invention. Suitable surfactants include those described above inregard to the personal care composition embodiments of the presentinvention. Such cleaning compositions may optionally further compriseone or more of water miscible organic solvents, such as alcohols andglycols, and/or one or more additives.

Suitable additives are known in the art and include, for example,organic builders, such as organophosphonates, inorganic builders, suchas ammonium polyphosphates, alkali metal pyrophosphates, zeolites,silicates, alkali metal borates, and alkali metal carbonates, bleachingagents, such as perborates, percarbonates, and hypochlorates,sequestering agents and anti-scale agents, such as citric acid andethylenediaminetetraacetic acid, inorganic acids, such as phosphoricacid and hydrochloric acid, organic acids, such as acetic acid,abrasives, such as silica or calcium carbonate, antibacterial agents ordisinfectants, such as triclosan and cationic biocides, for example(N-alkyl)benzyldimethylammonium chlorides, fungicides, enzymes,opacifing agents, pH modifiers, dyes, fragrances, and preservatives.

In an embodiment the home care or industrial cleaner benefit agent isselected from the group consisting of soil release agents, fabricsoftener, surfactants, builders, binders, bleach and fragrances.

In an embodiment the home care or industrial cleaning composition forcleaning fabrics or hard surfaces comprising, the composition of thepresent invention and a surfactant and a home care or industrial cleanerbenefit agent.

In an embodiment the composition is a detergent composition andcomprises: the polymer, at least one detersive surfactant, and abuilder.

The invention also encompasses a method for cleaning a substrateselected from the group consisting of a hard surface and a fabric,comprising applying the composition of the present invention to thesubstrate.

It should be apparent embodiments other than those expressly describedabove come within the spirit and scope of the present invention. Thus,the present invention is not defined by the above description but by theclaims appended hereto.

What is claimed is:
 1. An ethylenically unsaturated monomer according tostructure (D.I):

wherein R₁ and R₅ are independently absent or a bivalent linking group,R₂ and R₆ are independently a bivalent polyether group, R₃ and R₇ areindependently absent or a bivalent linking group, and R₄ and R₈ areindependently a moiety having a site of ethylenic unsaturation; whereinR₉ and R₁₀ are independently selected from the following structuresD.Ia, D.Ib, D.Ic, D.Id:

or a C₂-C₃₀ branched or linear alkyl group or alkenyl group.
 2. Themonomer of claim 1 wherein R₂ and R₆ are independently selected from—[CH(R₂₀)CH(R₂₁)O]_(x)—, wherein x is an integer of from 0 to 100, andR₂₀ and R₂₁ are independently selected from any of the following: H;—CH₂OH; phenyl; —CH₂Cl; a C₁-C₃₀ straight or branched alkyl or alkenyl;—CH₂OR₂₂ wherein R₂₂ is C₁-C₃₀ straight or branched alkyl or alkenyl,phenyl, or alkyl substituted phenyl; or R′COOCH₂— where R′ is C₁-C₃₀straight or branched alkyl or alkenyl.
 3. The monomer of claim 1 whereinR₄ and R₈ are independently according to structure (D.XV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.
 4. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₃-C₁₄branched or linear alkyl group.
 5. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₉-C₃₀branched or linear alkenyl group.
 6. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₆-C₁₄branched or linear alkyl group.
 7. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₉-C₁₄branched or linear alkenyl group.
 8. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₈-C₁₂branched or linear alkyl group.
 9. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₂₃-C₃₀branched or linear alkenyl group.
 10. The monomer of claim 1 wherein theC₂-C₃₀ branched or linear alkyl group or alkenyl group is a C₄-C₁₂branched or linear alkyl group or alkenyl group.
 11. A copolymer ofunsaturated copolymerizable monomers, said unsaturated copolymerizablemonomers comprising, based on total weight of monomers: A. about 0-60weight percent of at least one C₃-C₈ alpha beta-ethylenicallyunsaturated acidic monomer; B. about 15-70 weight percent of at leastone nonionic, copolymerizable C₂-C₁₂ alpha, beta-ethylenicallyunsaturated monomer; and C. about 0.05 to 30 weight percent of at leastone ethylenically unsaturated monomer according to claim 1 wherein theethylenically unsaturated monomer is nonionic and hydrophobic.
 12. Thecopolymer of claim 11, wherein the copolymer is pH responsive.
 13. Thecopolymer of claim 11, comprising, based on total weight of monomers: A.about 5 to 60 weight percent of the at least one C₃-C₈ alphabeta-ethylenically unsaturated acidic monomer; B. about 15-70 weightpercent of the at least one non-ionic, copolymerizable C₂-C₁₂ alpha,beta-ethylenically unsaturated monomer; and C. about 0.05 to 30 weightpercent of at least one ethylenically unsaturated monomer according toclaim 1 wherein the ethylenically unsaturated monomer is nonionic andhydrophobic.
 14. The copolymer of claim 13, wherein the at least oneC₃-C₈ alpha beta-ethylenically unsaturated acidic monomer (A) is presentfrom about 25 weight percent to about 60 weight percent based on totalmonomer weight.
 15. The copolymer of claim 13 wherein the at least oneC₃-C₈ alpha beta-ethylenically unsaturated acidic monomer (A) isselected from a group consisting of methacrylic acid, acrylic acid and acombination thereof.
 16. The copolymer of claim 13 wherein the nonionicmonomer (B) is alkyl acrylate.
 17. An aqueous composition, comprisingwater and the pH responsive copolymer of claim
 12. 18. A method forthickening an aqueous emulsion, comprising: forming a blend by blendingwith the aqueous emulsion an amount of the pH-responsive copolymer ofclaim 12 to thicken the aqueous emulsion when pH of the blend isadjusted to a pH in the range of about 6.5 to about
 11. 19. Thecopolymer of claim 11, wherein the at least one C₃-C₈ alphabeta-ethylenically unsaturated acidic monomer is at least one C₃-C₈alpha beta-ethylenically unsaturated carboxylic acid monomer.
 20. Thecopolymer of claim 13, wherein the at least one C₃-C₈ alphabeta-ethylenically unsaturated acidic monomer is at least one C₃-C₈alpha beta-ethylenically unsaturated carboxylic acid monomer.